Metallurgical furnace



Nov. 8, 192

B., TALBOT METALLURGICAL FURNACE Filed March 1e. 1927 4 She ets-Sheet 5 oaoouooauoooooo A NSQ Nov. 8, 192 7.

B. TALBOT.'

METALLURGICAL FURNACE Filed March 1e 1927 4 Sheets-She-et 4 Patented Nov. 8, l?.

rsa i stares raies.

METALLURGICAL sunnites;

Application filed March 1G, 1927,V Serial No. 175,852, and in. Great Britain March 5, 1926.

This invention relates to metallurgicall furnaces such, for example, as described in the (3o-pending patent application Seria] No. 5981 filed 3l January 1925, in Which the furnacehas separate. from its rmain hearth and at one or both ends thereof one or lmore baths for melting metal or keeping metal molten, the bath or baths being'heated by Waste gases from the furnace. I @ne object of the present invention is to maintain such bath or baths at a higher temperature than is possible by the use only of the Waste' gases from the main furnace, so as to melt a solid metal chargein a shorter time or, if molten metal is poured into'4 the bath, to obtain a higher temperature in the liquid metal, and also to facilitate the further reiining of such metal in the bath.

Another object of the invention is to minimize in regenerative metallurgical furnaces the drop of temperature due tothe cooling of the regenerator of either or both of the fuel elements supplied to the main furnace. Another robject is to provide a lregenerative metallurgical furnace.l With f means whereby an auxiliary chamber or bath at either end of the main furnace traversed by .the Waste gases therefrom vcan be alter` natively or simultaneously .raised 1 to a higliertemperature than cany be derived from Vthe aforesaid Waste gases.

l/Vith these objects a gas port or ports and also, if necessary, air ports are provided at,

a convenient point or points in the Walls. of the auxiliary bath chambers and are connected With suitable sources of supply, the `combustion of the gaseous fuel so supplied in the space immediately above the bath serving to increase the temperature of the bath to the required extent above that obtainable from the heat derived from the v Waste gases from the main furnace, orto maintain or increase the temperature of f 1 either or bothof the gaseous fuel elements as by passing it Vthrough an air recuperator' which may be formed vvithi-nor ad]acent` to v the clieclreryvorlr` of the main regenerator of the furnace. 1 y

The vgas ports in they Wall of the auxiliary bath chamber or chambers may be supplied with producer gas or cokeoven gas, vor oil) gas, and a by-pass to the furnace staclrinay l be provided to divert some. of the combustion lgases of the bath chamber from the regen'-V erator orfromtlie main furnace, according as the bath chamber is at the outlet end,

for the time being of the vmain furnace, or

l `at the inletend thereof. inthe caseof a re,-

versibl'e regenerative furnace such as "described in the copending patent application..` hereinbefore referred to, the gasjet or jets.k

the time being is the inlet'y end for gas and air, i the drop .of the temperature of the air, sup- 1 plied to the main furnace hearth throughthe coolingV of the checkerworlrof the air ive-p ,generator is minimized. In "this case the Whole or, kif there is a by-pass, a part rofthe combustion products of the jets heating the auxiliary bath pass withy the heated air tof the main furnace, but the proportion ofusuch ivaste gases to the totalvolume of gas and air supplied for combustion in the main fury nace is insuflicientto affect to any sensible extent thewcombustion of the heating gases or the metallurgical process resulting therefromin the mainliearth of the furnace. Similarly, at the other"` end of the furnace the proportionv of hot Waste gases diverted i from, the regenerator to the stack. is also inconsiderable. Y i i The invention less kdiagranimatieally y ink the accompanying is illustrated more vfor` drawings, in which Fig. l is a cent-rail longitudinal section of one end of a tilting fur-k nace adapt-ed tobe heated by colte-oven gash,

and having an auxiliary bath and an air regenerator' at each end of the main furnace 'structure; Fig. 2 is a sectional plan of Ithe n look portion Vof the furnace indicated in Fig. l;

.'Fig. 3 is aside elevation, partly in section on the line A-B iny Fig. 4c, of a modifiedv tilting furnace having an auxiliary bath,.an air regenerator and a gas regenerator at both ends;

, Fig. 4 is a plan, partly in section, of the' furnaceshoivnjin Fig. 3, in which the auxiliary through the line C-D in Fig. 3; Fig. 6 is a section on line E-F looking in the direction of arrow X in Fig. 4'; Fig. 7 is a' longitu- Vgas and air connections with the auxiliary line G-H in Fig. 7; Fig. 9 is an' illustration y of a side-blowing blast device, a tuyre thereof being shown in full lines blowing upon the surface of an auxiliary bath, and in broken lines, blowing into the auxiliary bath, Fig. 10 is an illustration of the nozzle part `lit-ted with a controllingV valve at 5, An auxiliary bath chamber Gai-ranged tobe in` of a tuyre device out of action and outside the wall of an auxiliary bath chamber; Figs.

11 and 12 are respectively a vertical section anda horizontal. section of a furnace structure with theV auxiliary baths provided with devices for preheating the vair admitted thereto, and Fig. 13 is Vasection on the line f' J-K inF ig. 11; Fig. 11i is a diagram showing, to a smaller scale, the auxiliary gas and air connections illustrated in Fig. 4l.

Corresponding parts .in 'the several furnace'portions illustrated are indicated by the same reference numerals. A In the construction shown in Figs. 1 and 2, the referencenumeral 1 denotes the main hearth chamber formed in the tiltable furnace structure 2 carried by a number of supports carrying suitable roller bearings 3 arranged to allow of the hearth being tilted, gas supply piping being' indicated at 4 and communication with the main hearth charnber 1 and with an air regenerator 8, is formed separately from the structure 2. In the wall 7 of the chamber .6 are provided one "or more ports 9 for an auxiliary gas supply,

and if necessary with one or more ports 10` for an auxiliary air supply. The auxiliary bath'y structure may be provided with a taphole 11 having a pouring spout 12, and with a flue 18 for the conduct of waste gases to a stack or, preferably, to where they can be utilized. f Y

. In the arrangement shown in Figs. 3 and 4, wherein producer gas may be used for heating the main hearth chamber, there is an4 air regenerator 8 and a gas regenerator 1a at eachend of the furnace. `Auxiliary gas supply connections for heating the bath 6 are shown at 15 and arranged to'communicate with the two gas regenerators 14 under the control of valves 16 and 16 respectively. Auxiliary air connections with the bath are shown at 17 and arranged to communicate with the twol air regenerators 8 under the control of valves'18 and 18. K

The gas and air connections 15 and 17 are provided each with two sets of additional valvesnumbered 19, 19, 20, 20 respectively, which valves can be operated as may be desired to cut oli' or admit gas and air or either of them from or to one or other or to both of the auxiliary bath chambers 6.

The diagram depictedA in Fig. 11i shows the two pairs of rcgenerators 8, 14, the auxiliary and air connectionsl, 17, the control valves 16, 16 and the two sets of valves 19, 19 and 20, 20 arranged as in Fig. 4, but drawn to a smaller scale. In the diagram the valves 16 and 18, the valves 19 and 20 are. all shown open, while valves 16', 18', 19 and 2O are closed, in order that auxiliary gas and air yfrom 'the regenerators ron the lefthand portion of F ig. 14 may be supplied to the auxiliary bath above the 'air regenerator 8 in the right-haiid portion of that igure. It is thus seen that the' portions of the gas and air connections at one end of the furnace may be active, while the portionsat the other end of the furnace'are rendered inactive.

By providing va regenerative furnace such as that in Figs. 3; and 4, vwith the necessary tlues and by properly sett-ing the valves on the auxiliary connections 15, the auxiliary gas jets for heating the two auxiliary baths can be each maintained llit for both directions of'worlring, so'that lthe auxiliary gas jet or jets at that end of the furnace which for thetime being is the inletend for the gas or the gas and' air forheating the main hearth., can be injected, butA only in an inconsiderable quantity. finto thef mainY stream of air supplied to that hearth for the purpose described above. v

The piping indicated at 21 and 21 in Fig.y

i is for the conduct of waste gases from the regenerators 8 to the chimney stack of the Y furnace plant.

y In :the end portion of the furnace, which is illustrated'in Figs.' -7 and 8 and is fed with coke-oven gas through the piping l to ai'ixed main hearth 1, the lauxiliary bath chamber 6 is arranged to tilt or rock sideways on roller bearings 25 in a manner that has been previously proposed for sidewaystilting main hearths.v rlhe level of the auxiliary bath is approximately the same as that of the bathin the main hearth, and the auxiliary bath chamber is provided with a pourl,

ing spout 26 in one side wall and in the oposite are formed nassaOes 27ffor blast tui :s v

yeres for purposes described above.

A convenient form of a side blast vtuyre device 28 is shown in Fig. 9,v the vdevice being mounted on a portable'carriage 29. The

passage 27 in thewall 7 ,of` the auxiliary bath chamber', through which the tuyere nozzle 28 can, by'shifting the carriage, be pushed into the bath chamber, is adapted' to be closed when thevtuyre nozzle is withdrawn from the chamber as itis shown in Fig. 10, by means of a rising and falling counterweighted door 80. The `tuyre is pivotally mounted at 31 on the carriage 29 so that it can, by operating the associated lever 32, be placed-in a position to blow f upon the surface of the bath (as indicated in full lines in Fig. 9) or in a position to yan auxiliarybath-( than is possible with thel Waste gases 'from the `furnace hearth, a gas ort or 1Jorts 22 and alsoV if necessaiI air ports l23 are provided at a convenientpointV f or points in the Wall 'of the bath chamber 6 and are connected with suitable sources of supply, the combustion of the gas so supplied in the space immediately above the bath servinf` to increase the temperature of the bath to the. requiredextent above that obtainable fromy the heat -derived from the Waste gases from the main' furnace hearth. The air supply may be preheated, if desired, as by passingit through an air recuperator or heating chamber 24 which may be formed Within or adjacent to the checkerwork of the main regenerator lof the furnace. i

The gas ports may be supplied with producer @as obtained leither direct from theA gas main or froma heated regenerator, or coke-oven gas, natural gas or oilk gas, and a by-pass 25 to the furnace stack preferably through the waste heat boiler may bepro-k vided to divert some of the combustion gases of the'bath chamber from the regeiirator or froml the main furnace, according astlie bath chamber is at the outlet end fortlie time being of the main furnace, or at the inlet end.

It may be pointed* out that the increasedA temperature of the auxiliary bath obtained in the manner described facilitates the fur- 1 ther refining of the contents of the bath, as

lby the introductionof 'iron oxide, or by a blast of air upon or, into the bath, With or without the addition oflime or limestone or other suitable refining agent, such as a suitable liquid slag obtained from the main hearth or from another furnace and introduced into the bath in its Amolten state.

the bath can be maintained keeps the liquid metal charge ina condition more suitable for its transference by a ladle or other lconvenient means to the mainv hearth of the same furnace, or of another furnace, fory further treatment.

Under suchconditions that when a blast of air is blown into or upon the bath some of the carbon is oxidized from the liquid metal, the carbonio oxide thus produced is burned and part of the heat so generated increases the heat in the auxiliary bath, while part passes to the airregenerator, when this blowing is accomplished in the auxiliary chamber which is at the outlet end, for the time being, lof the main furnace.

The molten metal to be refined in the-aux iliary bath may be metal obtained from Ya blast furnace direct, or from a mixer, or may be metal melted in a cupola or other furnace,

and the hearth of anfauxiliary bath for use for refining 'ispreferably a basic, one, a'lthough itmay alternatively be acid.

Having thus described the nature of the` said invention andthe best meansl know-'off carrying". the same into practical e'llect, l.

claim h f e l .Y

El. A regenerative* metallurgical furnace having at one end thereofan auxiliary Abath chamber communicating With the air f re generator of the furnace, and having means for burning gaseous fuel in said chamber,

whereby the temperature of the air passing Vfrom the regenerator to the main furnace is increased. n y n 2. A regenerative metallurgical furnace having at each end thereof an auxiliary bath chamber communicating With the air regenerator at the respective.. ends of the furnace, and means for burning gaseous fuel in a chamber aforesaid, wherebythe temperature of the air passing from 'the i'egenerator to the main furnace is increased.

3. A regenerative metallurgical furnace havin@ a main hearth and an auxiliar hearth `heated by-Waste products'` of combustion `from themain hearth, means for flowing air in reverse directions alternately over said,v '.liearths, and auxiliary heating means adjacent tosaid auxiliary hearth for heating the contents thereof and ythe air flowing to.

`rections alternatelyfover saidhearths, and

auxiliary heating means adiacent to each ofV said auxiliary hearthsy for supplementing the heating of the contents thereof by products flowing from said main hearth. i

5. A' regenerative vmetallurgical furnace havingY a main hearth and an auxiliary hearth heated by waste products of combustion from the main hearth, means for supply-k ing a stream of air to said main hearth, `aux- `iliary heating means adjacentv to said auxiliary hearth for heating the contents thereofl and said airstream, said auxiliary heating means comprising means for supplying heated air to said auxiliary hearth independently of the main Vair stream.

6. A regenerative metallurgical furnace'y lhaving, affmain hearth and an auxiliary hearth heated by waste products ofcoinbus.

tion from the main hearth, means for supplying @alternately .oppositely directed air streams tok said hearths, auxiliary 'heating means adjacent to said auxiliary hearth for heating the contents thereof and said Jair streams, a stack, and meaiisfor by-'passing a portion of the productsof combustion from said auxiliary heating means to' said stack. 7. A regenerative metallurgical furnace hearth, means for flowing air` in reverse directions alternately over said hearths, air regenerators :alternately heated by gases flowing from said hearths and heating air flowing t0 said Vhearths, and supplementary heating means for minimizing temperature variations in 'air {How/ing, over said auxiliary 10 hearths to said main hearth and comprising devices for directing blastsof air into contact vvith combustible constituents lofy the'` contents of said auxiliary hearths.

In testimony whereof I have signed my. 15

name to this specification. e

BENJAMIN TALBOT. 

